@ -1,31 +1,49 @@
/ /
/ /
/ / Let ' s learn some array basics . Arrays are declared with :
/ / Let ' s learn some array basics . Arrays are declared with :
/ /
/ /
/ / const foo [ size ] < type > = [ size ] < type > { values } ;
/ / var foo [ 3 ] u32 = [ 3 ] u32 { 42 , 108 , 5423 } ;
/ /
/ /
/ / When Zig can infer the size of the array , you can use '_' for the
/ / When Zig can infer the size of the array , you can use '_' for the
/ / size . You can also let Zig infer the type of the value so the
/ / size . You can also let Zig infer the type of the value so the
/ / declaration is much less verbose .
/ / declaration is much less verbose .
/ /
/ /
/ / const foo = [ _ ] < type > { values } ;
/ / var foo = [ _ ] u32 { 42 , 108 , 5423 } ;
/ /
/ / Get values of an array using array [ index ] notation :
/ /
/ / const bar = foo [ 3 ] ; / / 5423
/ /
/ / Set values of an array using array [ index ] notation :
/ /
/ / foo [ 3 ] = 16 ;
/ /
/ / Get the length of an array using the len property :
/ /
/ / const length = foo . len ;
/ /
/ /
const std = @import ( " std " ) ;
const std = @import ( " std " ) ;
pub fn main ( ) void {
pub fn main ( ) void {
/ / ( Problem 1 )
/ / This " const " is going to cause a problem later - can you see what it is ?
/ / How do we fix it ?
const some_primes = [ _ ] u8 { 1 , 3 , 5 , 7 , 11 , 13 , 17 , 19 } ;
const some_primes = [ _ ] u8 { 1 , 3 , 5 , 7 , 11 , 13 , 17 , 19 } ;
/ / Individual values can be set with ' [ ] ' notation . Let ' s fix
/ / Individual values can be set with ' [ ] ' notation .
/ / the first prime ( it should be 2 ! ) :
/ / Example: This line changes the first prime to 2 ( which is correct ) :
some_primes [ 0 ] = 2 ;
some_primes [ 0 ] = 2 ;
/ / Individual values can also be accessed with ' [ ] ' notation .
/ / Individual values can also be accessed with ' [ ] ' notation .
/ / Example : This line stores the first prime in " first " :
const first = some_primes [ 0 ] ;
const first = some_primes [ 0 ] ;
/ / Looks like we need to complete this expression ( like ' first ' ) :
/ / ( Problem 2 )
const fourth = ? ? ? ;
/ / Looks like we need to complete this expression . Use the example
/ / above to set " fourth " to the fourth element of the some_primes array :
const fourth = some_primes [ ? ? ? ] ;
/ / Use ' . len ' to get the length of the array :
/ / ( Problem 3 )
/ / Use the len property to get the length of the array :
const length = some_primes . ? ? ? ;
const length = some_primes . ? ? ? ;
std . debug . print ( " First: {}, Fourth: {}, Length: {} \n " ,
std . debug . print ( " First: {}, Fourth: {}, Length: {} \n " ,